Self-cooled electric motor



Jan. 9, 1923. 1,441,460

A. G. SUTCLIFFE. SELF COOLED ELECTRIC MoToR-. FILED JAN. 21. 1922.

Patented Jan. 9, 1923.

UNITED STATES 1,441,460 PATENT OFFICE.

ARTHUR G. SUTCLIFFE, OF CHICAGO, ILLINOIS, ASSIGNOR TO ILG ELECTRIC VENTI- LATING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF LOUISIANA.

SELF-COOLED ELECTRIC MOTOR.

Application filed January 21, 1922. Serial No. 530,752.

T 0 all whom it may concern:

Be it known that I, ARTHUR G. SUTCLIFFE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Self-Cooled Electric Motors, of which the following is a specification.

This invention relates to improvements in self-cooled electric motors. The present improvement is designed more especially for use on electric motors used-on direct driven fans and blowers, and is based on the same broad principle as that disclosed in Letters Patent No. 831,284, granted September 18, 1906 to Robert A. Ilg, and in the later Letters Patent No. 1,244,334, granted October 23, 1917 to the same patentee.

The main object of the present invention is to provide'an improved means for conducting the cooling air into the hood or casing which covers the rear end of the motor, such improved air conducting means enabling me to advantageously utilize, as a part thereof, a structurally novel motor-supporting ring or cradle.

My invention, in one practical embodiment thereof, is shown in the accompanying drawing, in which Fig. 1 is a side elevation of a ventilating fan and electric motor therefor, the latter equipped with my improved cooling device;

Fig. 2 is a rear elevation of the same parts, as viewed from the right of Fig. 1, partly broken out and in vertical section;

Fig. 3 is a vertical section of the eccentric motor-supporting ring or cradle alone;

Fig. 4 is a horizontal section on the line 4-4 of Fig. 3, looking downwardly; and

Fig. 5 is an edge view of Fig. 4, viewed from the bottom of the latter.

Referring to the drawing, 6 indicates a vertical wall in which is a circular opening 7, fitted to which is a ring 8 formed with a radial flange 8 which fits against the inner surface of the wall 6 surrounding the opening 7. On the periphery of the flange 8 are attaching lugs 9 apertured for the passage of fastening screws b which the ring is secured to the wall 6. (3 11 the outer face of the flange 8 are other lugs 10 to which are secured by bolts 11 theouter ends of av pair of elbow-shaped arms 12, the inner ends ring or cradle 15. It will be observed by The advantages of this special construction.

will. appear later. The lower side of the cradle 15 is formed with a tapped boss 16,

in which is entered the upper threaded end of an elbow-shaped pipe 17. The lower horizontal end of the pipe 17 is threaded into a tapped sleeve 18 having a flange 19 apertured to receive fasteningscrews20 by which said sleeve is secured to the face of the lower attaching lug 9. This latter, at a point opposite the open end of the-pipe 17 is formed with an openingregistering with the latter, this opening preferably consist ingof the bore of a hollow boss 21 fitted to an opening 22 in the wall 6. p

The motor itself embodies the common and well known structure of an electric motor,'including the circular field frame 23 which is embraced and held by the ring or cradle 15.

In the lower side of the ring or cradle 15 directly above and communicating with the hollow boss 16 there is formed a shallow port or passageway 24 closed on the forward edge of the ring, but leading through its rear edge as clearly shown in Figs. 4 and 5.

The rear edge of the ring 15 is formed with a narrow countersunk shoulder 25 extending entirely around the same, on which is mounted theopen end of a hood 26 that completely encases all the parts of the motor in rear of the field frame 23; and it will be seen from Fig. 1 that the port or passageway 24 which, as stated, communicates freely with the upper end of the air induction pipe 17 leadsdirectly into the lower portion of the hood 26.

Covering the front end of the motor is another hood 27 which forms a support for-the shaft bearing and is formed in its upper portion with an opening 28 directly behind a ventilating fan 29 that is mounted on the armature shaft 30 of the motor.

Under the action of the fan 29 a current of cooling air is induced through the pipe 17 and passage 24 into the rear hood 26, whence the air flows through the field of the motorm ,a iineo bathing the pole pieces, field coils and armature of that latter, and flows thence through the front hood 27 and the opening 28 in the latter; the action and effect of'the air cur rent and its general direction of flow being substantially identical with that described in the aforesaid Letters Patent No. 1,244,334. In the aforesaid patent, however, the lower induction pipe is entered directly into the bottom of the hood. In my present invention the lower induction pipe 17 constitutes one of the supporting arms of the motor, and thence communicates with the rear hood through the passage way 24 formed in the bottom of the motor supporting ring or cradle.

By giving to this ring or cradle the eccentric form shown, there is, in the first place, a desirable distribution of metal, since the motor supporting strain is born almost entirely by the relatively thickened lower half of the ring, the upper half serving merely as a clamping element; and, in the second place, this thickening of the metal in the lower portion of the ring or cradle enables the formation of the air duct or passageway 2% between the pipe 17 and the interior of the hood 26. F or this latter purpose the eccentric form of ring is not indispensable but is preferred on acount of its simplicity and because alfording a perfectly circular support for the open end of the hood 26 and avoiding the necessity of irregular construction of the latter to fit the ring.

I claim 1. lln a self-cooled electric motor of. the character described, the combination of a motor, a cradle supporting the field frame of said motor, said-cradle having a relatively thickened lower portion formed with an air duct extending through one edge thereof, a hood enclosing the parts of the motor on one side of said cradle with its interior in free communication with said air duct, and an air inflow pipe connected into the lower thickened portion of said cradle and in free communication with said air duct,

2. In a self-cooled electric motor of the character described, the combination of a motor, an eccentric ring embracing and supporting the field frame of said motor and disposed with its thickest portion lowermost, said thickest portion being formed with an air duct extending through one edge thereof, a hood enclosing the parts of the motor on one side of said ring with its interior in free communication with said air duct, and an air inflow pipe connected into said lowermost thickest portion of said ring from beneath and in free communication with said air duct.

3. in a self-cooled electric motor of the character described, the combination of a motor, an eccentric ring embracing and supporting the field frame of said motor and disposed with its thickest portion lowermost, said thickest portion being formed with an air duct extending through one edge thereof, a circular hood mounted on said ring and enclosing the discharge end of said airduct and the parts of the motor on that side of said ring, and an air inflow pipe connected into said lowermost thickest portion of said ring from beneath, and in free communication with said air duct.

4. in a self-cooled electric motor of the character described, the combination of a motor, an eccentric ring embracing and supporting the field frame of said motor and disposed with its thicker half lowermost, said thicker half being formed at its lowest point with an air duct opening through one edge thereof, a circular hood mounted on said ring and enclosing the discharge end of said air duct and the parts of the motor on that side of said ring, an air inflow pipe connected into the lowest portion of said ring from beneath and in free communication with said air duct, and another hood enclosing the parts of the motor on the other side of said ring and formed with an air discharge openanrrrnn c. sn retrrrn 

